1. Technical Field
The present disclosure relates to a method for making a carbon nanotube structure, such as a carbon nanotube film, or a carbon nanotube wire.
2. Description of Related Art
Carbon nanotubes are tubules of carbon generally having a diameter of about 0.5 nanometers to about 100 nanometers, and composed of a number of coaxial cylinders of graphite sheets. Generally, the carbon nanotubes prepared by conventional methods are in particle or powder forms. The particle or powder-shaped carbon nanotubes limit the applications in which they can be used. Thus, preparation of macro-scale carbon nanotube structures, such as carbon nanotube films, has attracted attention.
A method for drawing a carbon nanotube film is disclosed in US pre-grant publication NO. 2008/0248235A1 to Feng et al., published on Oct. 9, 2008.This patent publication discloses a carbon nanotube film which is directly drawn from a carbon nanotube array on a substrate. The carbon nanotube film includes a plurality of successively oriented carbon nanotube segments joined end-to-end by van der Waals attractive force therebetween. Each carbon nanotube segment includes a plurality of carbon nanotubes substantially parallel to each other, and joined by van der Waals attractive force therebetween. This carbon nanotube film is a free standing film because the adjacent carbon nanotube segments are joined end-to-end by van der Waals attractive force therebetween.
Generally, a length of the carbon nanotube film is inevitably affected by the largest width of the carbon nanotube array or the largest width of the substrate. Thus, it is difficult to obtain a carbon nanotube film having a larger length.
What is needed, therefore, is to provide a method for making a carbon nanotube structure, such as a carbon nanotube film, or a carbon nanotube wire. The carbon nanotube structure has a length larger than a length of a carbon nanotube structure fabricated by the carbon nanotube array.